code: def tearDown(self) -> None:
      ray.shutdown()
  
file_path: ray/rllib/tests/test_pettingzoo_env.py
imports: from numpy import float32
  from pettingzoo.butterfly import pistonball_v6
  from pettingzoo.mpe import simple_spread_v3
  from supersuit import color_reduction_v0, dtype_v0, normalize_obs_v0, observation_lambda_v0, resize_v1
  from supersuit.utils.convert_box import convert_box
  import unittest
  import ray
  from ray.rllib.algorithms.ppo import PPOConfig
  from ray.rllib.env import PettingZooEnv
  from ray.tune.registry import register_env
label_desc: Use image node_id 2 for calling the TestPettingZooEnv obj's underlying member method code with example usage: obj.tearDown() without return types